Need to jump the thermostat to see if it is bad as the a/c unit does nothing -no-fan-no compressor-no hum

What color wires do you have? If it's just a gas furnace and a/c you should have R,W,G,Y
Just jump red and yellow together, but first disconnect them from the t-stat.

OK. Well I would hook the thermostat back up. Does the furnace have power? If so make sure you have 24 volts at the thermostat by using a voltage meter and checking the red wire. Does anything else work? Can you get the fan to run in the "ON" position? Let me know and maybe I can walk you through some steps and figure this thing out